Depth of Maximum Development of Extensive Air Showers by Radio Emission Data at Yakutsk EAS Array

Cosmic rays: air showers from low to high energies

“…• The features of the energy spectrum have been confirmed with improved statistics. The existence of the low energy ankle at ∼ 10 16 eV and of the second knee at ∼ 10 17 eV have been confirmed by IceCube [13], Yakutsk [11], KASKADE-Grande [10] and the TALE telescopes of TA [16]. The measurements of the position of the ankle at 5 × 10 18 eV by Auger [20,21] and TA [19,16] are in excellent agreement.…”

“…Unfortunately this quantity cannot be measured directly but has to be inferred from the measurement of the properties of the atmospheric showers, an inference affected by the large systematic uncertainties related to the hadronic interaction models. The mean value of logarithm of the mass number <ln A> at energies below 10 17 eV has been measured by the IceCube collaboration using coincident events in IceTop and the deep-ice detector [13], and with the Small Cherenkov Array in Yakutsk [24]. The measurements are shown in Figure 7 and both confirm that the composition becomes heavier from a few times 10 15 eV to 10 17 eV.…”

“…It is important for the ARGO-YBJ results to be confirmed by other experiments. • The IceCube [13] and Yakutsk [24] data shows that the composition becomes heavier from the first knee to the second knee. Above ∼ 10 17 eV the composition becomes lighter as confirmed by Yakutsk and the new measurement by Auger using the HEAT telescopes [25].…”

“…These features are clearly evident in the energy spectra measured by the Yakutsk and IceCube collaborations (see Figure 3). The Yakutsk spectrum is based on 20 years of continuous operation of the Cherenkov telescopes (1994-2014) [11]. The…”

“…A first measurement of the mean depth of the shower maximum by LOFAR using a sample of 118 showers is shown in the left panel of Figure 17 [84,102]. Another measurement of the mean X max based on the radio array installed in the Yakutsk site was presented in [103].…”